Surfacing runner



Nov. 6', 1948.. A .1. M. FISHER ETAL 'l 2,453,748 y l SURFACING RUNNER iFiled April 5, 1947 2 sheets-sheet l J. M. FISHER ET AL 2,453,748SURFACING RUNNER Nov. 16, 1948.

Filed April 5, 1947 fida/.3. y 3l 2 Sheets-Sheet 2 32 /fv EN Toes n f1/0 Mv /vz Fisk/5e m TTOE/VE'K Patented Nov. 16, 1948 UNlTEDjs/TfATEsPATENT OFFICE f' "2,453,743 A l j sURrAcING RUNNER o Jaim M. FisherjandMerle M. Ekins, Ford city,"`

Pa., assignors to Pittsburgh Plate Glass Company, Allegheny CountVPennsylvania y, Pa., a corporation of Application April 5, i947, serialNo. 739,720

s claims. (ci. 51-2o9i This invention relates to apparatus. forsurfacing sheets of glass, or the like, and it has particular relationlto a .bonded abrasive unit `and mountings therefor. j f

One object of the invention is to provide an improved mountinglforbonded abrasive surfacing units by which a unit can be firmly lheld overa greater portion of .its area while in application toworktobesurfaced.

Another object of thev invention is to provide an improved structureand` arrangement of a chuck and bonded abrasive elements adapted to bemounted upon a surfacing machine.

Another object ofthe invention is to provide improved mountings forbonded abrasive ele- Inents by which rigid connections are uniformlydistributed over the abrasive elements to prevent inequalities instresses and by which portions of the connections can be removedaccording to the degree of wear on the work-engaging` surface of theabrasive elements.` I

In the drawing: y l

Fig. 1 is a diagrammatic bottom` plan of a runner unit for a surfacingapparatus; Fig. 2 is a fragmentary horizontal section, on .a largerscale, taken substantially along the line II-II of Fig. 4; Fig. 3 isajfragmentary cross-section', on a larger scale, takensubstantially-along the line III-III of Fig. 1; and Fig. 4 is afragmentary side elevation of a runner unit. j z

In one form of the inventionillustrated,inthe drawing, an annular runnerassembly I I3 comprises a metal disk cap lII that is adapted to beYconnected to a runner supporting mechanism of a surfacing apparatus, andan annular groove I2 is formed inthe lower side of the disk. capadjacent `its rim. A segmental` annular abrasive structure I4 composedof bonded abrasive segments I5 has the upper edge portions thereofittedinto the groove I2 while the lower edges or rim portions I6 remainfree to` engage work to be surfaced. The assembly of abrasive segmentsI5 defines an annulus of substantially truncated conical form. Suitablecement Il secures the upper rim portion of the annularabrasive structureI4 firmly in the groove I2. `The surfacing segments I5 can be selected,as to composition,

from Well known types of bonded abrasive used in surfacing operationsaccording to the nature of the work to be surfaced.

Although the position of the runner assembly as shown in the drawing issuch that the axis of the annular structure I4 is' substantiallyvertical or upright, it is to be understood that such position `isillustrative for purposes of convenience in descriptionY andthatthestructure is adapted to operate in other positions.

position for LIn order `that the abrasive segments I5 may be mounted andheld in proper position to form an annular structure, al-series oftruncated conical metal rings I8, I9 and 20 of unequal diameters arerigidly secured to these segments by means of horizontal bolts 2|arranged radially of each ring. The rim portions of the rings arerabbeted, as indicated at 22, for they purpose of insuringicontinuity ofthe conical surfaces of the` rings along the joints defining the linesof division between adjacent rings and inconformity with the "contour ofthe innerV walls of the segmentalannular structure I4. Thethree ringsthus constitute `sectional ring structure. The smaller or upper ring I8is disposed at its upper edge in anannular groove 23 formed in the lowerside ofthe disk` cap II. The annular grooves I2 and 23 are'arranged `soas to be coaxial with each other and with respect to the annularstructure I4 and rings I8, I9 and 20.

The bolts 2I are screwthreaded into tapped openings 24 in the rings`which have lugs 26 welded thereto, as indicated at 21, to v insureproper depth of the tapped 3 openings. These bolts are spaced`circumferentially along each ring and disposedradially thereof.

The adjacent edges of the successivesegments I5 are spaced sufficientlytoreceive rows of the boltsv l2l that are connected to the rings I8, I94

to the extremitiesof theabrasive segments which v might otherwisecontact the bolts during assem- `ings 36 in the `central blyofthefsegments or during operation of the runner assembly. The outerends of the bolts are provided with clamping heads 32having convergingouter walls 33 which are coinplemental` tosimilar converging or beveledend walls or` faces 34 of the segments I5. The clamping heads 32arevrecessed, as indicated at 35, to `receive the heads of the bolts incountersunk relation.`

The Shanks `of these bolts extend through openportions ofthe clampingheads.` This arrangement of elements isdesigned kfor the purpose of lpreventing any projections beyond the outer circumferential surfacesofthe abrasive` segments. Suitable gaskets 3l composed `vof` yieldablematerial, such as ilber composition, rubber composition, or the like,are disposed` between opposed complemental faces 33e-34. By tighteningthe bolts 2I in the metal rings the surfaces 33 of the vclamping headsy32 of the segments I5 and against the cushioning ansah-is gaskets 31.The several inner faces of the segments I5 at locations on oppositesides of the respective bolts 2| are also cushioned by means of gaskets38 disposed between the segments I5 and the surfaces of the rings.

It is to be noted that the bolts 2I are disposed radially at pointsspaced circumferentially of each ring. After th'e abrasive segments havebeen a truncated cone, and means for demountably worn a predetermineddegree in their oper-ation,

the lower ring can be removed by releasing the bolts connected thereto,Upon releasing these bolts the ring is free to fall from the conical orflaring inner walls of the annular structure I4. In like manner, thenext ring I9 is adapted to be removed after the segmental abrasivestructure has been worn along its lowerrim to such extent th'at it isnearing the edge of such next ring I9. In this manner the segments I5can be firmly mounted with respect to the rings and supporting disk II,andthe several rings can beA successively removed according to thedegree of Wear on the surfacing rim, While still maintaining properrigid mounting and distribution of stresses in the annular abrasivestructure.

rIt is i-mportant that the segments be cemented firmly to the disk capII. The bond between the abrasive segments I5 and the metal disk in thegroove I2 can be effected by cementing with such materials as pitch,Roses metal (an alloy of bismuth, lead and tin) type metal or othereutectio alloys or magnesium oxychloride.

Although only one form of the invention has been shown and described indetail, it will be apparent tothose skilled in the art that theinvention is not so limited, but that various changes can be madetherein without departing from the spirit or scope of th'e invention asexemplified in the appended claims.

We claim:

1. In a runner assembly for surfacing apparatus, a runner cap of plateform, a ring connected edgewise upon the bottom of the cap, additionalrings disposed in coaxial relation to the rst ring, adjacent ringshaving rim portions overlapping in axial directions and having theirwall surfaces substantially ush with one another, bonded abrasivematerial defining an annular contour and arranged in coaxial relation tothe rings, each ring having a series of connections spaced at intervalscircumferentially of th'e ring and securing the ring and abrasivematerial in rigid relation.

2. A surfacing assembly comprising a supporting member, said memberhaving coaxial grooves in one side thereof, ring structure having a rimdisposed in one of said grooves and leaving an opposite rim free, bondedabrasive material defining an annular contour and mounted in the othergroove, said abrasivematerial including a surfacing rim extendingaxially beyond the free rim of the ring structure, and radialconnections Securing the annular abrasive material and ring structure inrigid relation.

3. In a runner assembly for surfacing apparatus, a supporting cap havingan annular groove on one side thereof, bonded abrasive material ofannular form having an upper rim thereof mounted in said groove, ringsdisposed coaxially in edge to edge engagement and coaxially of theannular abrasive material, and means for demountably securing the ringsseparately to the annular material, said rings having intertting edge toedge engagement holding adjacent vring edges against relative lateraldisplacement, and being successively removable therefrom.

connecting each ring section to the abrasive sections, adjacent marginalportions of said sections having interlocking means holding them againstrelative lateral displacement and said sections being free to fallaxially from one another upon release of said means.

5. In a rotatable runner assembly for surfacing apparatus and having anupright axis, a supporting cap having inner and outer coaxial grooves onthe lower side thereof, a bonded abrasive seg-mental annulus composed ofsegments defining a surfacing rim disposed in a plane transversely ofthe axis of the annulus and anchored in the outer groove, said segmentsbeing disposed successively about the circumferential extent of theannulus, adjacent segments having converging wall portions, metal ringstructure interfitting in coaxial relation with the segmental annulus inaxially spaced relation to the surfacing rim and having its upper rimanchored in the inner groove, said ring structure including ringsections with adjacent marginal portions of the sections in assembledrelation being interlocked against lateral displacement, each ringsection having radial openings therein registering with the lines ofdivision between the several segments, and fastening means separatelymounted in the openings of each ring section and having portionsdisposed in wedged relation on said converging wall portions to securein rigid relation the annulus and ring structure.

6. In a runner assembly for surfacing apparatus, a segmental annuluscomposed of bonded abrasive segments defining a surfacing rim disposedin a plane transversely of the axis of the annulus, adjacent segments ofthe annulus having oppositely beveled and juxtaposed extremities, metalring sections interfltting in coaxial relation with the annulus1adjacent marginal portions of the rim sections in assembled relationbeing rabbeted and interlocked against lateral REFERENCES CITED Thefollowing references are of record in the le of this patent:

UNITED STATES PATENTS Number v Name Date 508,773 Shipe Nov. 14, 18931,587,534 Lipps ai June 8, 1926 1,611,747 Heppenstall Dec. 21, 19261,797,526 Hoaglund Mar. 24, 1931 FOREIGN PATENTS Number Country Date190,028 Great Britainl Dec. 14, 1922

